Notes from the universe.

Discoveries, ideas, and the stories behind what we learn when we look up.

PlanetsExplainerNovember 5, 20261 min read

Why planet migration models need changing timescales

Near one 2:1 resonance, simulations show changing disk torques can defeat fixed migration and damping timescales.

S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO) · ALMA image of the disc around the young star TW HydraeLicense terms · CC BY 4.0. Converted from TIFF to WebP; responsive versions resized. No crop or overlay.

PlanetsExplainerNovember 5, 20261 min read

How Ganymede’s magnetic field constrains its interior

A measured surface field filters interior models, but assumptions leave multiple core compositions possible.

ESO/King & Fletcher · The moon Ganymede seen by SPHERELicense terms · CC BY 4.0. Resized and converted from the original TIFF; no crop or overlay.

PlanetsExplainerNovember 5, 20261 min read

Uranus’s electron belt: what one flyby can tell us

A Voyager 2 reanalysis and an Earth comparison suggest one possible mechanism, but leave its cause unconfirmed.

ESO · The Uranus system (VLT)License terms · CC BY 4.0. Converted from TIFF to JPEG; responsive versions resized and converted to WebP. Both dated panels retained.

PlanetsExplainerNovember 5, 20262 min read

Can a planet gap make two CO₂ ice lines?

One simulation predicts paired CO₂ ice lines and a wavelength test for the dust rings they create.

ALMA (ESO/NAOJ/NRAO) · ALMA image of the protoplanetary disc around HL TauriLicense terms · CC BY 4.0. Full frame resized from TIFF to JPEG; responsive versions converted to WebP.

PlanetsExplainerNovember 5, 20262 min read

More giant companions, or heavier ones?

A census of 719 stars separates how often giant companions occur from how their masses compare with the stars they orbit.

Michael (the_tahoe_guy) · Mount Hamilton- Lick ObservatoryLicense terms · CC BY 2.0. Full frame retained; resized and converted for web.

PlanetsExplainerNovember 5, 20262 min read

What TESS’s Neptune ridge actually measures

A population study finds a concentration of planets on short orbits. Understanding its comparison matters as much as the twofold headline.

GreenSpacealien original diagram · Castro-González, Table 1

PlanetsExplainerNovember 5, 20262 min read

Why a comet’s HCN cargo may not survive delivery

A model of early Earth’s comet bombardment separates carrying organic molecules from delivering a concentrated supply that survives an impact.

ESO, Colin Snodgrass (Max Planck Institute for Solar System Research, Germany) · Rosetta's cometLicense terms · CC BY 4.0. Source two-panel processing retained; resized and converted for web.

PlanetsExplainerNovember 5, 20262 min read

Why Chariklo’s rings need more than a Roche limit

A fluid model explores how a small body’s shape changes its disruption boundary, while leaving the origin and survival of its rings open.

ESO/M. Tewes · Danish 1.54-metre telescopeLicense terms · CC BY 4.0. Resized and converted for web.

MissionsExplainerNovember 4, 20261 min read

How ERMIS-3 held a laser link on target

An ERMIS-3 laser downlink tests tracking; AUTh reports 1 Gbps capability and link-budget potential up to 10 Gbps.

GreenSpacealien original diagram

EarthUpdateNovember 4, 20261 min read

MetOp-SG-B1 moves to a cleanroom

MetOp-SG-B1 has left storage in French Guiana as ESA prepares for reactivation, checks, fuelling and a planned year-end launch.

Don-vip · MetOp-SG inside Airbus Defence and Space Astrolabe facilities 11.jpgLicense terms · CC BY-SA 4.0. Resized and converted for web; this adaptation is shared under CC BY-SA 4.0.

AstronomyExplainerNovember 4, 20261 min read

Gaia22alz: a proposed trigger for nova winds

A model links Gaia22alz’s wind to its companion but cannot simulate the transition.

Mariko Kato and Izumi Hachisu · Figure 8License terms · CC BY 4.0. White backing; resized and converted.

PlanetsNewsNovember 4, 20261 min read

TOI-4129 b at the Neptune ridge’s inner edge

A preprint reports confirmation of a 3.27-day planet using transits and stellar-wobble measurements.

Gianni0088; © 2012 Giovanni Tessicini · Red sky at TNG.jpgLicense terms · CC BY-SA 4.0. Resized and converted for web; these versions use the same license.

AstronomyNewsNovember 4, 20261 min read

SN 2019qem’s modeled 9-solar-mass eruption

The fit places it two years before explosion; wind speed, gas shape and light production affect the estimate.

Legacy Surveys / D. Lang (Perimeter Institute); figure: Majumdar et al. · SN 2019qem: decades of extreme mass loss before the explosion of a luminous, long-lived Type IIn supernovaLicense terms · CC BY 4.0. Figure cropped from the paper page, resized, and converted for web.

AstronomyExplainerNovember 4, 20262 min read

How laser guide stars help telescopes see sharply

Lasers make sodium beacons that help adaptive-optics systems measure atmospheric blur, while natural stars provide a reference for overall image motion.

ESO/A. Berdeu · Stars on demandLicense terms · CC BY 4.0. Resized and converted for web display.

EarthUpdateNovember 4, 20261 min read

Sentinel-6B enters operational service

Sentinel-6B began operational service on 30 October after cross-validation with its twin. An earlier NOAA bulletin already listed its data.

GreenSpacealien original diagram

PlanetsUpdateNovember 4, 20261 min read

ED138 gains an older record

Preprints add old ground and space observations to Rubin’s dwarf-planet candidate; its diameter remains uncertain.

GreenSpacealien original diagram

AstronomyNewsNovember 4, 20261 min read

JWST measures a redshift beyond 10 for a galaxy candidate

An October 30 arXiv preprint reports CW-LRD-z10’s spectroscopic redshift; its classification and power source remain uncertain.

ESO/UltraVISTA team. Acknowledgement: TERAPIX/CNRS/INSU/CASU · Highlights of VISTA’s deep infrared view of the COSMOS fieldLicense terms · CC BY 4.0. Resized and converted for web.

MissionsNewsNovember 4, 20261 min read

Hera resolves the pair it came to study

Hera's 18 October 2026 image separated Didymos and Dimorphos during its approach to the post-impact survey.

GreenSpacealien original diagram

SpaceflightHighlightsSource era 2024November 4, 20262 min read

Ariane 6’s 2024 debut proved the upper stage—and exposed one unfinished test

The July 2024 maiden flight deployed eight passengers after two Vinci burns, but an auxiliary-unit shutdown prevented its planned final burn.

ESA · Ariane 6 media kit coverLicense terms · CC BY-SA 3.0 IGO. Resized and converted for web.

PlanetsHighlightsNovember 4, 20262 min read

A 2025 study reported a planet candidate in TWA 7’s debris ring

A JWST source observed in 2024 fits a cool companion, while follow-up supports the interpretation without yet testing shared motion.

GreenSpacealien original diagram

PlanetsHighlightsSource era 2024November 4, 20262 min read

A 2024 study found a close planet around Barnard’s Star

ESPRESSO measured a short-period sub-Earth-mass world; later instruments tested the signal and refined which other signals count as planets.

ESO/Digitized Sky Survey 2 Acknowledgement: Davide De Martin · Widefield image of the sky around Barnard’s Star showing its motionLicense terms · CC BY 4.0. Resized and converted for web.

PlanetsHighlightsNovember 4, 20261 min read

A 2026 CHEOPS highlight: AU Mic c’s transit timing reversed

Timings from 2024 moved AU Mic c back toward its predicted schedule; the size and cause of the variation remain uncertain.

ESO/Digitized Sky Survey 2 · Wide-field view of the sky around the nearby star AU MicroscopiiLicense terms · CC BY 4.0. Resized and converted for web.

AstronomyExplainerNovember 4, 20261 min read

Four spectral peaks point to two rings around a dead star

An unusual light spectrum supports a two-ring model around white dwarf J1328−1450, with alternatives still considered.

ESO/L. Calçada · Detecting two rings of debris around the white dwarf J1328−1450License terms · CC BY 4.0. Resized and converted for web.

MissionsHighlightsSource era 2024November 4, 20262 min read

Juice's 2024 Moon-Earth assist

The double assist sent Juice toward Venus before later legs to Jupiter.

GreenSpacealien original diagram

MissionsNewsNovember 4, 20261 min read

Euclid finds its first new comet

C/2026 S1 turned up in galaxy-survey images; catalogues confirmed a first for the mission.

GreenSpacealien original diagram

AstronomyHighlightsNovember 4, 20262 min read

2024 highlight: polarized light maps magnetic clues near the Milky Way’s black hole

A 2024 polarization image revealed a robust spiral pattern, while the surrounding plasma and magnetic field still require interpretation.

EHT Collaboration · A view of the Milky Way supermassive black hole Sagittarius A* in polarised lightLicense terms · CC BY 4.0. Resized and converted for web.

AstronomyHighlightsSource era 2024November 4, 20262 min read

Gaia BH3: a black hole found by a star’s wobble

The 2024 announcement described a massive dark companion and a tentative clue from its star.

ESO/L. Calçada/Space Engine · Artist’s impression of the system with the most massive stellar black hole in our galaxyLicense terms · CC BY 4.0. Resized and converted for web.

GuidesGuideNovember 3, 20262 min read

Measuring stellar distances with parallax

Parallax links a star’s annual apparent shift to distance; noise and calibration determine confidence.

GreenSpacealien original diagram

GuidesGuideNovember 3, 20261 min read

How gravity assists redirect spacecraft

A moving planet can trade a tiny amount of orbital energy when its gravity bends a spacecraft’s path.

GreenSpacealien original diagram

GuidesGuideNovember 3, 20262 min read

What exoplanet spectra can and cannot show

Transit spectra suggest chemistry, but overlapping signals limit claims about atmospheres and life.

GreenSpacealien original diagram

SpaceflightNewsNovember 3, 20261 min read

Vega-C’s 2026 VV30 flight used a Vespa adapter for two satellite releases

Sentinel-3C rode above FLEX; the spacecraft separated in sequence, about an hour apart, into different orbits.

ESA–G. Porter · Vega-C upper stage shaker testLicense terms · CC BY-SA 3.0 IGO. Resized and converted for web.

SpaceflightHighlightsNovember 3, 20262 min read

Vega-C’s 2024 return followed two Zefiro-40 nozzle tests

After a 2022 second-stage failure, Vega-C returned with a redesigned nozzle and two test firings behind it; its launch record now extends through 2026.

contains modified Copernicus Sentinel data (2024), processed by ESA · Svalbard, Norway, seen from Sentinel-1CLicense terms · CC BY-SA 3.0 IGO. Resized and converted for web.

EarthNewsNovember 3, 20262 min read

Sentinel-1 observed Petermann Glacier’s August 2026 calving

A floating section over 76 km² detached after years of fracture growth; radar dates the event but does not assign its cause.

contains modified Copernicus Sentinel data (2026), processed by ESA · Petermann ice tongue April–August 2026License terms · CC BY-SA 3.0 IGO. A frame was extracted from the sequence; resized and converted for web.

EarthHighlightsSource era 2024November 3, 20262 min read

EarthCARE launched in 2024 with four linked sensors

Radar, lidar, multispectral imaging and radiation measurements track different parts of the cloud–aerosol system.

ESA–S. Corvaja · Cleaning EarthCARELicense terms · CC BY-SA 3.0 IGO. Resized and converted for web.

EarthHighlightsSource era 2025November 3, 20262 min read

Biomass launched in 2025 to map forest structure

P-band radar measures woody biomass as a carbon-storage proxy; repeated scenes will support estimates of forest height and stock change.

ESA · Bolivian forest and landscape from BiomassLicense terms · CC BY-SA 3.0 IGO. Resized and converted for web.

AstronomyNewsNovember 3, 20261 min read

A radio signal traces comet MAPS before its breakup

Radio observations track April gas outbursts; the inferred mass loss depends on modelling assumptions.

ESO · APEX antennaLicense terms · CC BY 4.0. Resized and converted for web.